Lest you think that Nate Silver is just some number-crunching nerd:

Let's be frank: Norm Coleman doesn't have much of a future in electoral politics. Defeated Presidential candidates sometimes have nine lives, but defeated Senatorial candidates rarely do, and in his career running for statewide office, Coleman has lost to a professional wrestler, beaten a dead guy, and then tied a comedian. He doesn't have much to lose by fighting this to its bitter conclusion.